With the significant increase in CTN for low-tier advanced spells, I would like to see Metaphysical Understanding errata'd to be more useful. Currently, Metaphysical Understanding and Prodigy do not stack (making MU sub-par if you have Prodigy). I would like to see Metaphysical Understanding changed to either lower the CTN of advanced spells by 2 or to explicitly stack with Prodigy (the other option would be to make Prodigy stack with other talents but that would make an already good talent even better). If someone is willing to invest the 2 talents just to become better at advanced spells, I see nothing wrong with them having an effective +3 for casting them.

The best you can do with advanced spells that I can see if prodigy, metaphysical understanding, and spell affinity x2 (requiring tier 2) which gives you an effective +4 (current) or +5 (proposed) to cast a specific adapted advanced spell which seems fine given the 4 talents required.

no they don't stack which is why its a +2,

General skill use (+1) vs. Specific Skill use (+2)

I figured that would be the answer but was hoping it would be different. With mis-applying Prodigy and Metaphysical Understanding (eg stacking), I had gotten to the point of being accepting of the significantly higher CTNs for advanced spells (still far from liking them but I appear to be in the minority). Now I'm back to thinking they are definitely too high again (4 starting ranks, d10, +3 ranks during T1, MU = 3d10+9 for advanced spell = 25.5 avg which is likely to get an unadapted T1+T1 advanced spell off but highly unlikely to get one off with even a single adaptation; more reasonable 3 starting ranks and d8 gives 2d10+d8+8 which is only 23.5 (less than 50% likely to cast a typical T1+T1 advanced spell at 1.10 (which is way too difficult to me)). The extra +1 from stacking Prodigy and MU wasn't huge but pushed the chances up a little bit.

I still think the CTN is way too high on T1+T1 advanced spells (and would much rather see other limits placed on them such as slowing down rather than high CTN). However, I've said that often enough now that I'm sure everyone is aware of my views and I"m stuck living with the majority view (advanced spells are pretty much useless until mid T2).